Method of removing starch from the binder on glass cloth



E. H. BALZ Jan. 19, 1954 METHOD OF REMOVING STARCH FROM THE BINDER ONGLASS CLOTH 2 Sheets-Sheet 1 Filed May 28, 1951 INVENTOR EMIL H. BALZBYW I ATTORNEYS Jan. 19, 1954 I E. H. BALZ METHODOF REMOVING STARCH FROMTHE BINDER 0N GLASS CLOTH Filed May 28, 1951 2 Sheets-Sheet 2 GLASSCLOTH PLUS BINDER CONTAINING STARCH AND on.

SOLUTION OF HYDROT ROPIC AGENT SOAK CLOTH IN HYDROTROPIO SOLUTION FORABOUT ONE HOUR WATER AT l50'-' I70 F WASH WITH HOT WATER- TO REMOVESTARCH DRY THE GLASS CLOTH GLASS CLOTH PLUS OIL IGNITE AT ABOUT lCLEANED. CLOTH INVENTOR ENIIL H. BALZ.

' ATTORNEYS isrequired' I in" order Patented Jan. 19, 1954:-

Emit H; .Balz]; Waterville,

Fibers Inci iWaterville, Ohio,v

Ohio

' N GLASS CLOTH 0hio, assignor to Glass a. corporation-of 1o Claims.(01434-2) This; invention relates to -glass cloth. .iMor'eparticularlythe invention relates: to: a .treat ment for glass cloth torenderthe-same: useful inthe' making of. 'laminations withresin'ous' pressuresteam mast: and: pulled into longs fine fibers. The individual 1 fiberis smooth; suhstanti'ally cylindrical and normally has: a diameter orabout- .00G21 -t'o 10'00'40' The fibers may then be grouped in suchfashion asto' form. a threadof parallel fibertand thereafter a group ofthe continuous fibers is'isent to the: textile machines" forweaving intocioth=.-

Irrord'er' tominimize friction in: processing the fibers-while theyareibeing drawn: out are: treated- Withfll water dispersion at alubri'cant of binder material prior to formation otlthe grouper Thisbinder materiall which generally consists; of" a vegetable lubricating"oil;- starch: and very 7 small amounts of cation e. wetting-* anddispersing agents: etc; coats fibers and reiriains 'thereon inthefinished glassclothi This inderis pres'-' ent to" the extent ofabout1.5% to- 2 .Q%- Weight on the dry fi'nishedglassclo'th i Thepresence o'fbihd'eraids in thetextiiie operation but seriously affects the abilityoiithe glass form 1 laminates with other materials, as synthetic'resins. Accord" when' it desired-to fii'rm such laminatestreatment oftfie glass cibth to' remove the binder material toxebtain satisfactoryadhesibns' between the=cloth and' the resin. 7 r

is-i iequently desirable to: ascertain percentages of oil and starch ina gi ven binder tonetermine the-application to: which a giir'en 'gi assfabric is suitable.-

Present known methods-for the-removal of the b'iirder'requi're-amongother-s cps the-treatment otthe--cl'et'h=at temperatures of the orderof: 690 to -106 forprol'onged periods; generally 55 fi'ii hoursi'methods, -of-course; seriously hinder production; require-an excessiveamount or equipment roraeiven production} and the overa l'lare-ekceedihgly eiq'aer-is'ive.- "fine-present invention provides-a newand improved method to determining the-percentages c t-oil and starch-ina given binder material;

The present invention contemplates-- the" 'provision 'of a novel-'nietho'd for the" removal of the sterciiiof 'the lbi'nder' materialofglass "ciothi 'Iiieinvention-further contemplates a'- method 2:. l ofproviding 2i scrupulously clean glas;s--cloth surface particularlysuitable for combining with resinous compositions;

The: invention also contemplates the provision of a production methodfor the clean-ing of the glasscloth. which eliminates the necessity forlarge storage space requirements during the processing steps; I

I have found that these and other obiects of the invention may beattained. by" treating the glass: cloth containingthe: oil-starchbinder" ma terial with a solution: of urea at modera-t'e ternperatures'. The starchand o'th'e'i' agents of the binder are therebyremoved immense-insane which retains the oil component oi th'e" binderthereon. Thereafter the oil may b'e removed from the fabricto: providea' vthoroughly clean glass 7 by (a) the use: of: a caustictreatmentasdescribed in co-pending applicatiom Seriai No. 228,623, filedMay 28, 1951, or (b) bythe use of an oxidizing agent as; described in mycopending appl ic'ationr $ue'r'ial No. 2285624;- filed May 28; 1951, or(c-) by a hatch-operation, or (61 by treatment in anautoclavewith air oroxygen under pressure.

In the practice: of the invention the glass cieth containing thefistarchand oil hinder soak-ed for. about-a half hour" in water solutioi of ureahaving a concentration of about 5 to- 2 9 percent and containingwetting"and} detergent agents These agents are used to l c'wer' the surf-aceten-' sion of the-urea-and permit-thesame to thorough 1y wet the" glassfabric and accordingly act to shorten the time of treatments Heatingtheurea solutionis' also (at assistance in-penetration (if-thebinder-material.

r The water dispers'ible constituents of thee-bin der; including-thesmall amounts of: wetting: and detergent components presenttherein; andthe starch, are substantiallyv completelt removed' by theaction of theurea solution-leaving the: oil

component of the binder on the glass.-'- 'Any smail' amount oi thesesubstances remainingoh the glass; with the exception of the-oil and thecationic agent, maybe then-completelyremoved hy washing the cloth" withhot wateri- Th'e oil' constituent of the binder as s'etfbtth in thisapplication, unless otherwise spec'ifi any indicated, will beunderstood-to include a e cationic'ageht which serves toretairf'the oilo he:- fabric. Since the quantity of this agent is very small it willnot materially affect the process? Thus this method of cleaning theglassrovides a. facile procedure for the determination ot the quantity of oilin a givenbinder material for the oil, as noted hereinbefore, may thenbe readily removed from the glass cloth by treatment with a strongalkali such as sodium hydroxide or a strong oxidizing agent as potassiumchlorate, and thereafter exposing the cloth to moderate temperatures, orif preferred the oil may be removed by treatment of the cloth withoxygen or air under pressure in an autoclave.

The treatment of invention is adaptable to all oil-starch bindermaterials and in substantially all proportions of these components. Theoil of the binder is generally a lubricating oil of vegetable origin,such as castor, hydrogenated cottonseed, olive and coconut. Highlyunsaturated oils due to their instability to light are not usuallyemployed in the lubrication of fibers for glass cloth manufacture, butif so employed under selected conditions would also be removable fromsuch cloth by the process of invention. The starch of the binder may beany of the normal starches of commerce and may include the slightlyhydrolyzed or dextrinized materials. In addition to these primarycomponents, one or more substances such as gelatin, borax, polyvinylalcohol or wetting and dispersing compounds are normally used in thebinder to facilitate application thereof to the cloth during manufactureand are readily removed from the cloth by action of the urea.

The cationic agent employed in the binder wiil however, as notedhereinbefore, remain on the cloth with the oil after treatment with theurea, and will be subsequently removed with the oil by ignitionprocesses.

The concentration of the urea may vary from 5 to 20 percent, aconcentration of 5 to percent water solution in general beingsatisfactory. The more concentrated solutions, while faster acting, arelimited in their use due primarily to cost considerations.

Wetting and detergent agents which may suitably be employed in the ureasolution include Triton N-100, a product of Rohm and Haas Company whichis a concentrated wetting agent and detergent designed primarily for usein the textile trade. Such an agent assists in the wetting andpenetration of the binder which is of itself somewhat water repellentdue to the oil content and shortens the time required for action of theurea. Triton N-100 is an aryl alkyl polyether alcohol soluble in allproportions in cold water and in most organic compounds. Other wettingand detergent agents having similar properties may be satisfactorilyemployed.

The invention will be more fully understood by reference to thefollowing detailed descripton and appended drawing wherein:

Figure l is a diagrammatic representation of apparatus used in thepreferred embodiment of the invention; and Figure 2 is a flow sheetillustrating the process of the invention.

Referring to Figure 1, there is shown a roll of glass cloth I producedfrom standard E glass, the fibers of which during manufacture weretreated with an aqueous binder material consisting by weight of about 2%of hydrogenated cottonseed oil (Pureco), about 8% of partiallydextrinized starch (Globe Gum), about 06% of gelatin, about .13% ofpolyvinyl alcohol, about .2% of Tween 81 (partial esters of fatty acidsand hexitolanhydrides combined with polyoxyethylene chains), about .4%of onyx cation X (fatty imadazoline derivative), the balance being waterand a very small amount of borax to bring the pH of the dispersion intothe range of 6.0 to 6.6. This binder material, minus the water content,is present to the extent of about 1.8% by weight on the dry glass clothroll shown at l.

The roll of glass cloth I is shown mounted upon a stand 2 and may beappropriately unreeled and passed over an idler roller 3, into a tank 4containing a 10% aqueous solution of urea, indicated generally at 5.This solution also contains approximately .05 to 0.1 of 1% by weight ofthe solution of Triton N- (an aryl alkyl polyether alcohol soluble inall proportions in cold water and in most organic compounds) and ismaintained at a temperature of about 175 to 195 F. The cloth is rerolledin the solution on stand 6 and permitted to soak for about one-halfhour, whereupon it is removed from the urea solution and stored as at 7to await further processing.

It is clear that a number of rolls may be subjected to the action of theurea at one time as indicated at 8, 9 and that a small storage spaceindicated generally at I0 will accommodate a considerable number oftreated rolls,

The urea-treated roll may preferably immediately after the steepingoperation, or on removal from thetemporary storage at ill, be mounted ona reel II from which it is unwound and passed continuously over rolls I2, l3 and I4 and under water sprays indicated generally at I5. This washwater has a preferred temperature in the range of F. to F. andeffectively removes all traces of starch, gelatin, polyvinyl alcohol,etc. which may remain after the urea treatment. The well known iodinetest for starch may be employed to determine whether the starch has beencompletely removed by the wash water, an end point which with theoil-starch binder materials under consideration, will be attained in amatter of a few minutes of washing. Any or all of the rolls over whichthe cloth passes may be driven and the speed of operation for a givenproduction arrangement may be readily determined to permit completecontinuous washing. A shallow pan i6 beneath the sprays directs spentwaste water to drainage or alternatively the spray 5 may be providedwith wash solution from tank 5 in which case the solution isrecirculated for reasons of economy. A combination of a urea solutionspray followed by a water spray may be effectively employed.

The washed cloth containing only the oil and cationic constituents ofthe binder is then passed under a spreader roll I7 and dried in oven [8at a temperature of about 200 F. to 300 F. Upon leaving the oven theroll of glass cloth is wound on a reel as shown at Is. This roll maythen be treated as described in my co-pending applications referred tohereinbefore, to remove the oil including the cationic agent and providea perfectly clean glass cloth useful for laminations with resinousmaterials.

Briefly this method consists of treating the cloth containing the oilwith a strong alkali such as .1 of 1% of sodium hydroxide and a pH ofabout 11 to 13, and after removal of the excess of alkali the oil may beburned from the cloth by subjecting the same to temperatures in therange of 650 F. to 750 F. for approximately one minute, after which anyslight discoloration on the cloth may be completely removed therefrom bytreatment with a 1% sodium hypochlorite solution and the cloth thenagain washed. After drying the cloth will be thoroughly cleansed and theloss of weight by these latter operations will represent the amount ofoil in the original binder.

The cleaned cloth is then in a very satisfactory condition forlamination with resinous substances in the manner known to the art.

It will be clear that by dryingand weighing the roll of cloth prior tothe start of the described treatment and again after drying in oven ofthe present invention provide a process for the I quantitativedetermination of the starch and oil constituents of the binder, but alsoprovides a method which materially reduces the time cycle for thecleaning of a roll of glass cloth as presently practiced in production.Thus the urea treatment requires an hour or less and the washing only amatter of minutes. Since the alkali or oxidizing treatment describedfully in'the coremoval of the oil will require less than three hours, itis readily seen that the whole process of the complete cleaning maybecarried .out in less than five hours, a material improvement-over theseveral days now customary in the art. I

Further the present invention is adapted to production methods thateliminate the tie-up of expensive equipment and space inherent to thepresent production methods.

-All glass compositions suitable for use in glass I fabrics may betreated by the process of invention and no. decrease in the strength ofthe fabric is occasioned thereby. I

Further the treatment of invention similarly to the alkali and oxidizingtreatments set forth in my co-pending applications results. in 'asmoother and softer fabric than the prior art processes provide.

It will be understood that this invention ceptible to modification inorder to adopt it to different usages and conditions and accordingly, itis desired to comprehend such modifications within this invention as mayfall within the scope of the appended claims.

' Iclaim:

- 1. In a'process for the removal of hydrophilic materials from a binderon glass cloth the step of soaking the glass cloth in an aqueoussolution of urea.

c 2. Ina process for the removal of hydrophilic materials from a binderon glass cloth the steps of soaking the glass cloth in'an aqueoussolution of urea, and washingthe cloth to remove all traces of thehydrophilic materials.

3. In a process for the removal of starch from oil-starch binder onglass cloth, the step of pending"applicationsreferred to above for the 6soaking the glass cloth in an aqueous solution containing 5 to 20percent by weight of urea.

4. In a process for the removal of starch from an oil-starch binder onglass cloth, the steps of soaking the glass cloth in a 5m 20 percentaqueous solution of urea at temperatures in the range of 170 F. to 190F., and thereafter washing the glass cloth with hot water.

5. In a process for the removal of starch from an oil-starch binder onglass cloth, the steps of soaking the glass cloth in an aqueous solutionof urea containing a wetting and detergent agent.

6. In a process for the removal of starch'from an oil-starch binder onglass cloth, the steps of soaking the cloth for about one-half hour in a5-20% .water solution of urea containing a wet-- ting and detergentagent, the temperature of said solution being in the range of 170 to 190E2, and thereafter washing the glass cloth with hot water.

7. A process for the removal of oil-starchbinder material from glasscloth comprising the steps of soaking the glass cloth in a 5-20% watersolution of urea at temperatures in the range :of 170 19o F. to removethe starch of the binder, and thereafter heating the cloth atatemperature of about 1200 F. to remove the, oil constituent of thebinder from the glass cloth.

8. A process for the quantitative determination of the oil in a binderon glass cloth which binder contains oil, starch and water dispersibles,comprising the steps of weighingthe cloth with the binder thereon,steeping the cloth in an aqueous solution containing 5-20% by weight ofurea to remove the starch and water dispersibles from the binder, dryingthe cloth, thereafter weighing the cloth containing the oil constituissus- I ent, igniting the portion of the binder remaining on the cloth toburn oh the oil constituent, and again weighing the cloth. 9 A processfor the removal of starch from an oil-starch binder on glass clothcomprising the steps of soaking the glass cloth with an aqueous solutioncontaining a urea and a wetting agent at a temperature in the range or"about 170 F. to 190 F. forabout one-half hour, and thereafter washingthe cloth with warm water.

10. A process for the removal of starch from I an oil-starch binder onglass cloth, comprising the steps of soaking the glass cloth in anaqueous solution containing approximately 10% by weight'of urea, andthereafter washing the glass cloth with water at a temperature of aboutF. to F. a I EMIL H. BALZ. References Cited in the file of this patentUNITED STATES PATENTS Number Name Date 2,407,483 Ebaugh Sept. 10, 19462,607,359 Oesting Aug; 19, 1952

1. IN A PROCESS FOR THE REMOVAL OF HYDROPHILIC MATERIALS FROM A BINDEROF GLASS CLOTH THE STEP OF SOAKING THE GLASS CLOTH IN AN AQUEOUSSOLUTION OF UREA.